Rubber playing ball



Sept. 12, 1939. c, A WEBB 2 2,172,425

I RUBBER PLAYING BALL Filed May 16, 1937 C'ha/rlesv e66,

"wa /M Patented Sept. 12, 1939 UNITED STATES PATENT- OFFICE nonnsn. mmd BALL Charles A. Webb, Lebanon, Pa., assignor to 0.

l3. Webb 00., Laban Pa, a conartnersbip composed of O. B. Webb and Grace 1. Webb Application May 10, 1937, Serial No. 141,810

-10 Claims. (01. 273-85) iii scholastic athletics. Such balls are relatively expensive, particularly for elementary school games and practice work, and there is a decided demand for an inexpensive rubber practice ball, simulating substantially the leather covered ball in size,

16 weight, feel and bounce. I

The problem of making an. inflated rubber playing ball to simulate a leather covered athletic ball iii-size, weight and appearance is not dimcult and involves merely the making of an ordi- 20 nary inflated rubber ball of proper size and thickness to conform to the'standard sizes and weights of corresponding leather covered athletic balls. Such balls, howevenhave' not heretofore corresponded to the leather covered athletic balls.

25 in resilience or bounce, as the rubber compounds commonly used in the manufacture of inflated playing balls provide a too lively ball, particuiarly when inflated to an extent to have a. feel or handle corresponding to a similar standard 30 leather covered ball. This is particularly disadvantageous in connection with inflated rubber soccer balls, foot balls and basket balls, as the lively or highly bouncing ball leads to a very dimcult style of play than the less lively leather 35 covered standard ball.

I have discovered that a compound conta rubber as a principal ingredient, combined with stiifening ingredients which will increase the tensile strength, lower the specific gravity of the i compound as well as soften it for suitable molding under heat is highly satisfactory for the manufacture of hollow inflated rubber balls having the characteristics'oi appearance, feel, resilience, stiffness and weight of standard leather L covered balls of the types above described.

While the invention is not restricted to the manufacture of any particular type of inflated athletic ball, I have illustrated in the accompany drawing a suitable construction of basket ball 0 which may be made according to the invention.

In the drawing- Fig. 1 is a plan view of the ball; and

Fig. 2 is a detail sectional view thereof.

According to the invention, the ball ill may be 5 or" any desired size and shape to correspond to a standard leather covered athletic ball, as for example, a foot ball, soccer ball, volley ball or basket ball, the latter being selected as an illustrative embodiment. The ball advantageously is formed of pre-shaped halves cemented together 5 along a median line, and thereafter vulcanized in a mold as is usual. Preferably the ball is inflated through a. self-closing valve ll of suitable type and construction so that it may be inflated with air to a proper pressure, this beingpreferl0 able to the .so-calied gas filled balls wherein the pressure cannot be accurately regulated. Preferably the surfaces of the curing molds are engraved to produce irregular dimpled designs of convex form on the surface of the ball, as at l2, to

imitate tanned pigskin or other leather used in the manufacture of standard leather covered athletic balls. Also the molds are constructed to mold into the body of the balls grooves l3, imitating seams of a leather covered ball and imitation lacing l4, and imitation stitching l5.

In order that the inflated rubber balls may possess a resilience and stiffness, substantially corresponding to the resilience and stiffness of corresponding standard leather covered balls, I preferably form the balls of a compound composed of rubber, a stiflening and deadening ingredient, preferably a mineral powder, such as carbon black or magnesium carbonate, and thermo-plastics, such as wax, glue, shellac or 80 paramn tosoften the surface of the rubber by the curing heat so that the leather design may be embossed therein, combined with usual curing agents.

Preferably the compound may include the following- Pounds Rubber 100 stiffening ingredient 30-80 A thermo-plasticiser 10-40 0 and usual curing agents.

'lhe rubber ingredients may be pure rubber or partly pure and partly reclaim, as is well understood. To this a. substantial amount of stiffening ingredient is added to stiffen the rubber and increase the tensile strength of the compounds. A mineral, such as carbon black and magnesia carbonate, have been found highly suitable for this pu pose and either materially stiif- 5 ens and increases the tensile strength of the compound when mixed with the rubber.

Such compound could not be molded readily, as for example, in vulcanizing molds, where an accurate ornamental design, such as imitation g5 leather, is to be produced on the surface of the ball. Accordingly, I add to the compound a suitable thermo-plasticiser such as wax, paraflln,

glue or shellac which will act to soften the compound. during the vulcanization to permit the compound to flow ,to the shape of the mold, but which will act to stiffen the compound upon cooling. This thermo-plasticiser also functions to decrease the resilience of the compound.

In the manufacture of certain athletic rubber balls it is desirable to lower the speciflc gravity of the compound so as to more accurately simulate the standard leather coverball in weight and feel. Accordingly, the stiffening ingredient may include in the above stated example, from 10 to 40 pounds of a lightening stiffener, for example cellulose, such as wood flour, cotton flock, rayon flock or the like. Such cellulose is highly advantageous as it does not soften the cured compound but on the other hand increases its stiffness.

It will be noted that the various ingredients compounded with the rubber, excepting the usual curing agents, add to the stiffness of the compound, and therefore decrease the resiliency of the ball, when inflated. In addition to these stiffening properties, the carbon black or magnesium carbonate materially increases the tensile strength of the ball, and the cellulose lowers the specific gravity of the compound so that the ball may be of substantial thickness to give'the desired feel to the ball. Similarly the thermo-plasticiser adds stiffness in the finally cured article, but when subjected to the heat of vulcanization, softens the compound and permits it to flow to the contour of the molds. It is thus possible to mold the compound during vulcanization to produce a lightly dimpled surface having a realistic appearance of leather. I

A hollow playing ball of any of the above named types and of proper size, shape and weight made of rubber and a compound as disclosed above, will correspond when properly inflated substantially in resilience, stiffness and feel to the more expensive corresponding standard leather covered balls of the usual bladder inflated design and may be satisfactorily used in practice by elementary schools, permitting a style of playnot difiering radically from the style of play required when using the standard leather covered balls. a

I am aware that heretofore some of the ingredients mentioned above have been compounded with rubber for the manufacture of other,

non-analogous articles. However, .so far as I ,am aware neither these nor similar ingredients other than those simulating leather covered bladstiffening ingredient adapted to stiffen thecom' pound and increase the tensile strength, and an ingredient capable of softening the compound to render it moidable under heat of vulcanizaa stiffening ingredient adapted to stiffen the compound and; increase the tensile strength, and an I ingredient selected from the group consisting of wax, glue, shellac and paraflin capable of softening the compound to render'it moldable under heat of vulcanization but capable of increasing the'stiflness of the compound upon cooling.

3. A hollow rubber sports ball having a dimpled surface resembling tanned leather, said ball being formed-of a compound containing rubber, stiffening ingredients adapted to increase the ten sile strength of the compound and a thermo-plasticiser to soften the compound under heat, to permit the ornamentation of said surface.

4'. A hollow rubber sports ball having a dimpled surface resembling tanned leather, said ball being formed of a compound containing rubber, a stiifening ingredient and a thermo-plasticiser adapted to soften the compound under heat to permit the ornamentation of said surface.

5. An inflated rubber playing ball formed of a vulcanized compound of rubber, a stiffening ingredient selected fromthe group consisting of carbon black and magnesium carbonate, to in-- crease the stiffness and tensile strength of the compound and a thermo-plastic ingredient se-. lected from the groupconsisting of wax, glue, shellac and paraflln to soften the compound under vulcanizing heat to permit molding, but upon cooling to stiffen and decrease the resilience of the compound.

sisting of wax, glue, shellac and paraffin to soften I the compound under vulcanizing heat to permit molding, but'upon cooling to stiffen and decrease the resilience of the compound.

7. An inflated rubber playing ball formed of a vulcanized compound. containing rubber and a stiffening ingredient in substantial amounts, 30 to per cent by weight, of the rubber content, adapted to stiffen the compound and increase the tensile strength, and an ingredient capable of softening the compound to render it moldable under heat of vulcanization but capable of increasing the stiffness of the compound upon cooling.

8. An air inflated rubber playing ball of desired appearance and shape corresponding to a leather covered athletic balL of desired type, said ball composed of a cured compound of rubber, a stiffening ingredient to lower the resiliency of the ball to substantially correspond to the resiliency of such leather covered-athletic balls and an ingredient capable of softening the compound to render it moldable under heat of vulcanization but capable of increasing the stiffness of the compound upon cooling.

9. A hollow rubber sports ball having a dimpled surface resembling tanned leather, said ball being formed of a compound containing rubber, a

stiffening ingredient including a cellulose material adapted to lower the specific gravity of the compound and a. thermo-plasticiser adapted to soften the compound under heat to permit the ornamentation or said surface.

10. A hollow rubber sports ball having a dimpled surface resembling tanned leather, said ball being formed of a. compound containing rubber, a summing ingredient including a. material selected from the group comprising wood flour, cotton flock or rayon flock adapted to lower the specific gravity of the compound, and a, thermo-piasticiser adapted to soften the compound under heat to permit the ornamentation of said surface.

- CHARLES A. WEBB. 

